Acute Changes in Endothelial Function in Germ Cell Tumor Patients Treated With Cisplatin and Untreated Germ Cell Tumor Controls

Endo-PAT2000 testing is done six times during the study. Baseline Assessment Time 1 Cycle 1, Day 1 (Pre-chemotherapy)Time 2 Cycle 1, Day 1 (After 1st dose of cisplatin), Time 3 Cycle 1, Day 2 (Before second cisplatin dose of cycle 1), Time 4 Cycle 1, Day 5 (After last cisplatin dose of cycle 1), End-of-Study Assessment Time 5 (14-34 weeks from Time 1; e.g., 1-12 weeks following completion of the last cycle of first-line chemotherapy) Long-Term Follow Up Assessment Time 6 (24-30 months from Time 1)

Time 1: A baseline assessment will be performed in the fasting state including Endo-PAT2000, vital signs, waist circumference, fasting blood draw, \& urine sample. This will be considered Day 1 of the study for this group of patients. Time 2 (2-5 hours from Time 1): Two to five hours after Time 1, patients will undergo assessment of blood pressure \& heart rate, including orthostatics \& Endo-PAT2000 testing. Time 5 -- End of Study visit (14-34 weeks from Time 1): At a time point 14 to 34 weeks later than Time 1 patients will undergo study testing in the fasting state. This includes Endo-PAT2000 testing, vital signs including orthostatics, waist circumference, fasting blood draw, \& urine sample. The Surgery-Only Group will not have any assessment at Time 3 (Day 2) or Time 4 (Day 5) due to logistical concerns. Long-Term Follow Up Assessment Time 6 (24-30 months following Time 1)